A team of researchers at Ohio State University (OSU) spent the past two years developing a clean way of harnessing the power of coal and have recently found great success in their research scale combustion system. The team is now able to harness clean coal energy chemically without combustion with air, while capturing 99% of the carbon dioxide produced from the reaction as reported by Environmental News Network.

Combustion is the main mechanism used to harness energy from coal. All existing coal-burning processes consume oxygen to produce heat. The downside, however, is that it also produces a large amount of pollutants, such as nitrogen and sulfur oxides, which are difficult to contain and are harmful to the environment. OSU researchers found a way to harness the energy from coal through what they call Coal-Direct Chemical Looping (CDCL).

CDCL mixes tiny iron oxide beads to carry oxygen to spur the chemical reaction with coal, which is grounded into a fine powder. This mixture is then heated to high temperatures, where the materials react with each other. Carbon from the coal binds with the oxygen from the iron oxide to produce heat and almost pure carbon dioxide that rises to the top of the chamber where it is then captured. The excess heat harvested in this process produces water vapor to power steam-turbines to generate electricity. Researchers reported that each unit can produce about 25 thermal kilowatts. Pure carbon dioxide is separated and recycled, the iron beads are exposed to air inside the reactor becoming re-oxidized, allowing the beads to be re-generated almost indefinitely and the coal ash is removed and disposed of safely.